Re: [PATCH v4] exec: load_script: Do not exec truncated interpreter path
From: Linus Torvalds
Date: Sun Feb 17 2019 - 12:30:39 EST
On Sun, Feb 17, 2019 at 1:09 AM Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> +static inline char *next_spacetab(char *first, const char *last)
> + for (; first <= last; first++)
> + if (spacetab(*first))
> + return first;
> + return NULL;
I think this should be "next_terminator()" and also stop at NUL.
You do check for the NUL case here:
> + if (!next_spacetab(cp, buf_end) && *buf_end)
> + return -ENOEXEC;
but it means that if there's no space ot tab and it's a short file,
you pointlessly walk to the end. No?